OCT-based elastography for large and small deformations

Abstract

We present two approaches to speckle tracking for optical coherence tomography (OCT)-based elastography, one appropriate for small speckle motions and the other for large, rapid speckle motions. Both approaches have certain advantages over traditional cross-correlation based motion algorithms. We apply our algorithms to quantifying the strain response of a mechanically inhomogeneous, bi-layered polyvinyl alcohol tissue phantom that is subjected to either small or large dynamic compressive forces while being imaged with a spectral domain OCT system. In both the small and large deformation scenarios, the algorithms performed well, clearly identifying the two mechanically disparate regions of the phantom. The stiffness ratio between the two regions was estimated to be the same for the two scenarios and both estimates agreed with the expected stiffness ratio based on earlier mechanical testing. No single numerical approach is appropriate for all cases and the experimental conditions dictate the proper choice of speckle shift algorithm for OCT-based elastography studies.

Optical coherence tomography today: speed, contrast, and multimodality

“…3). OCT contrast enhancement (prerequisite 3) has been accomplished by introducing polarization-sensitive OCT, [24][25][26][27][28] phasesensitive OCT, [29][30][31][32][33] optical coherence elastography, [34][35][36][37][38][39] spectroscopic low coherence interferometry, [40][41][42][43] elastic scattering spectroscopy, 31,[44][45][46] and nonlinear interferometric vibrational imaging (NIVI), as well as employing endogenous or exogenous contrast. [47][48][49][50][51][52] In this paper, a recently developed contrast improvement for OCT, named label-free optical angiography, is reviewed (cf.…”

Optical coherence elastography for measuring the deformation within glass fiber composite

“…Nevertheless, speckle decorrelation is an inevitable phenomenon during the loading test of a specimen. The improvement on the tracking accuracy and measurement range [31,32] could be a direction for future work.…”

Optical coherence elastography – OCT at work in tissue biomechanics [Invited]

“…We shall return to the important topic of inverse modelling in Section 6. Algorithms for optimizing speckle tracking remained a focus for the few researchers in the field into 2006 [19]. Of course, interest in speckle metrology, and in efficient algorithms for speckle tracking outside of OCE, goes back a long way [20], and was also an active field in the first half of the 2000s [19,21,22].…”